1. Technical Field
The method and apparatus of this invention relate generally to an apparatus and method of trimming an unwanted portion of material from a meat product. More specifically, it relates to an improved apparatus and method of trimming portions from a meat product which is of an extended, rounded shape such as shanks, knuckles and the like. Meat products as used herein are meant to refer broadly to beef, pork, poultry, and fish muscles and the like. Materials to be trimmed may be fat, membranes or the like. Machines of the type disclosed herein are referred to generally in the art as automatic skinning machines, automatic trimming machines, or automatic de-rinding machines.
Currently, extended, rounded meat products must be trimmed by hand or manually on a machine. This creates the possibility of serious injury to the hands. Additionally, there is a large reduction in efficiency due to the time required to perform these tasks by hand. Alternatively, there are presently available automatic skinning machines adapted to trim unwanted portions from meat products such as the Maja GEA421, SBA420 and ESB441. Consequently, it is highly desirable to automate the process of trimming extended or rounded meat products.
2. Description of the Prior Art
Prior art devices for automatically trimming unwanted portions from meat products are well known in the art. However, these devices are generally limited to meat products which are flat.
An example of this type of prior art device is illustrated in Townsend, U.S. Pat. No. 3,613,154. This typical prior device consists of a pair of rollers with a sharp blade therebetween. One of the rollers, a feed roller, serves to frictionally engage the underside of the meat product as it enters the machine. The other roller a pressure roller, serves to maintain pressure on the top side of the meat keeping it engaged with the rollers and thereby urging it against the blade. The blade, being fixed in position, cuts the meat as the rollers force the meat past it. The trimmed meat may then be discharged by means of a belt or the like, located rearward of the cutting blade. Since the rotation of the rollers forces the meat product directly through the machine, only a flat meat product may be trimmed. Sending a rounded, extended circumference meat portion through such a prior art apparatus would result in the trimming of only a small tangential portion of material therefrom.
Consequently, the trimming of an unwanted portion from an extended, rounded shaped meat product such as knuckles, shanks and the like, had to be accomplished by hand either using a knife or a manual membrane skinning machine. These methods are extremely dangerous. Repetitive motion injuries, carpel tunnel problems, hand fatigue and hand lacerations are all possibilities resulting from hand skinning.
Safety glove apparatuses have been developed in order to address this potential for injury when hand trimming meat. An illustration of such an apparatus is Dubors, U.S. Pat. No. 5,025,175. This device uses a switch in the power signal of the machine which is controlled by a radio signal. If physical contact is made between the glove and the machine, the radio signal is interrupted, the switch is opened, and power is removed from the machine, shutting it off. A similar device is disclosed in Townsend, U.S. Pat. No. 4,996,742 wherein physical contact of the glove and machine causes an interruption in power to the machine.
Although the machines are designed to stop "substantially instantaneously," any delay is too long when the fingers are in close proximity to the blade. Thus, these methods are far from perfect and may instill a false sense of security in the operator, allowing him to think he is safe thereby perhaps causing him to lower his guard and actually increasing the possibility of injury. Additionally, even if the possibility of injury were eliminated, the inefficiency of such a method would remain. Consequently, there is a great need for an apparatus which is capable of automatically skinning these types of meat products.
An example of a prior art machine adapted to trim unwanted portions from rounded, extended meat product such as shanks, knuckles and the like, is the Maja SRA 8000 series. The basic operating principles of this machine are described in our U.S. Pat. No. 5,236,323 which is herein incorporated by reference. This machine is extremely useful in trimming unwanted portions from products such as insides, outsides, knuckles and shanks.
Therefore, an object of the present invention is to provide an improved apparatus and method of safely and automatically removing unwanted material such as fat, membranes and the like from extended, rounded shape meat.
Another object of the present invention is to provide an apparatus which is capable of trimming a variety of different sizes of meat products.
Another object is to provide an apparatus wherein the inclination of the feed apparatus may be varied to accommodate various type of products.
Another object is to provide an apparatus which may be easily and conveniently installed in an assembly line.
Another object is to provide an automatic trimming apparatus which may be suspended above a workstation.
Another object is to provide an apparatus capable of trimming material from a variety of meat product types such as beef, pork, fish and other muscles.
Still another object of the present invention is to provide an apparatus which is capable of trimming material from meat products of a variety of consistencies.
Yet another object of the present invention is to provide an apparatus which is capable of receiving a variety of operator inputs indicating various parameters associated with the type of meat product to be trimmed.
Finally, an object of the present invention is to sense the position of the meat product on the feed system such that the trimmer is capable of automatic initialization.